1. Field of the Invention
The present invention relates to a plasma display panel, particularly, to a plasma display panel equipped with an electrode structure which can perform readily a discharge between a scan electrode and a sustain electrode.
2. Description of the Background Art
Generally, a plasma display panel includes barrier ribs formed between a front panel and a rear panel. Together, the barrier ribs and the front and rear panels form cells. Each of the cells is filled with a primary discharge gas such as neon Ne, helium He or a mixed gas comprising Ne and He. In addition, each cell contains an inert gas comprising a small amount of xenon. If the inert gas is discharged using a high frequency voltage, ultraviolet rays are generated. The ultra-violet rays excite light-emitting phosphors in each cell, thus creating a visible image.
FIG. 1 is a perspective view showing the structure of a conventional plasma display panel.
As shown in FIG. 1, as to the plasma display panel, the front substrate 100 and the rear substrate 110 are parallelly combined with a given distance. The front substrate 100 includes a scan electrode 102 and a sustain electrode 103, both of which make a pair to form a plurality of sustain electrode pairs on a front glass 101 where an image is displayed. A plurality of address electrodes 113 are arranged in order to intersect with the plurality of sustain electrode pairs on the rear glass 111 in the rear substrate 110.
The front substrate 100 includes a scan electrode 101 and a sustain electrode 102, both of which are employed in controlling the discharge and light emission of the discharge cell. The Y electrode 101 and the Z electrode 102 each have a transparent electrode “a” made of a transparent ITO material, and a bus electrode “b” made of a metal material. The Y electrode 101 and the Z electrode 102 together form an electrode pair. The Y electrode 101 and the Z electrode 102 are covered with at least one dielectric layer 103 for limiting a discharge current and for providing insulation. A protection layer 104, having magnesium oxide (MgO) deposited thereon to facilitate a discharge condition, is formed on the dielectric layer 103.
In the rear substrate 110, barrier ribs 112 in the form of a stripe pattern (or well type), for forming a plurality of discharge spaces, i.e., discharge cells, are arranged in a parallel manner. Further, a plurality of address electrodes 113 for use in achieving an address discharge which results in the generation of ultraviolet light, is disposed parallel to the barrier ribs 112. Red (R), green (G) and blue (B) phosphors 114, for emitting visible light for image display upon address discharge, are coated on a top surface of the rear substrate 110. A dielectric layer 115, which protects the address electrodes 113, is formed between the address electrodes 113 and the phosphors 114.
Hereinafter, the electrode structure of a conventional plasma display panel is illustrated in FIG. 2.
FIG. 2 is a plane view showing the electrode structure of the conventional plasma display panel.
As shown in FIG. 2, the transparent electrode a and the bus electrode b of the plasma display panel are arranged in the front substrate with a stripe type, while the address electrode 113 is formed in the rear substrate (not shown) in the direction intersecting with the transparent electrode a and the bus electrode b.
A plurality of address electrodes 113 are arranged in parallel with the barrier ribs 112.
The electrode structure within the discharge cell of the plasma display panel is illustrated in FIG. 3.
FIG. 3 is a plane view showing the electrode structure within the discharge cell of the conventional plasma display panel.
As shown in FIG. 3, the rectangular transparent electrode a is formed in the front substrate. The transparent electrode a of a rectangular shape is positioned in the both sides where the bus electrode b in the discharge cell is formed and faces each other across the central part of the discharge cell.
Moreover, the address electrode 113 intersects with the transparent electrode a and the bus electrode b, separated with the transparent electrode a and the bus electrode b as much as a given distance in a discharge.
The erosion state of the MgO surface in the life test of the plasma display panel having the electrode structure is illustrated in FIG. 4.
FIG. 4 is a diagram showing the electric field distribution in the life test of the conventional plasma display panel.
As shown in FIG. 4, the density of the discharge stream in the domain where a dark colour is displayed in the discharge area is great in testing the lifetime of the plasma display panel.
In other words, a discharge is initiated in the intermediate domain of the ITO line width. As to the discharge path, the center region of the ITO electrode is longer in comparison with the peripheral region. As shown in FIG. 5, due to the discharge, the damage of MgO increases as it proceeds from the denotation 1 area to the denotation 4 area of FIG. 4.
Therefore, it can be noticed that discharges, which is initiated in the intermediate domain of the ITO line width and proceeds near to the bus electrode, are strongly occurred, while relatively weak discharges are occurred in the peripheral region of the ITO line width.
As described, as to the discharge of the plasma display panel, on the whole, since the discharge is unevenly generated, it is difficult to implement a white balance.
Moreover, although the ITO electrode area where a discharge is generated is fixed, which is not considered in the conventional plasma display panel. In result, there is a problem in that the fabrication cost of the plasma display panel is increased since the ITO which is expensive is used for the ITO electrode area in which a discharge is not generated.